These are two very small excerpts from quite a lengthy article. I encourage you to read the rest via the link below.
“A growing number of conservatives see birth control as part of an ailing culture that overemphasizes sex and devalues human life. Is this the beginning of the next culture war?”
“But the other twist is that emergency contraception apparently works in a manner similar to that of the ordinary birth control pill. That is to say, the pill, which contains the hormone progestin, also has three possible means of operation: by stopping ovulation, preventing fertilization or impeding implantation. If emergency contraception is a potential abortifacient, then the same would seem to be true for the pill, which tens of millions of women have taken over the past several decades. Dr. Rudd disputed this. ‘The scientific evidence is that emergency contraception is more likely to have a post-fertility effect than the routine birth control,’ he told me. But Dr. James Trussell, director of the Office of Population Research at Princeton University and one of the world’s leading experts on contraception, said: ‘That is completely wrong. The evidence is about the same for all hormonal methods of contraception. We can’t rule out a post-fertility effect for Plan B, and the same is true for the birth control pill.'” (Russell Shorto, “Contra-Contraception” in the May edition of the New York Times Magazine).